In U.S. Pat. No. 2,893,752, issued July 7, 1959 to Harry C. May, and assigned to the assignee of the present invention, there is shown and described a control valve device for so controlling pressure of fluid in an air spring interposed between a sprung portion and an unsprung portion of a vehicle as to support the sprung portion at a substantially constant preselected height relative to the unsprung portion irrespective of the load carried by the sprung portion. This control valve device embodies a spool-type valve that controls the supply of fluid under pressure to or the release of fluid under pressure from an air spring. The periphery of this spool valve is provided with a plurality of spaced-apart peripheral annular grooves in each of which is disposed an O-ring seal. This spool valve is shiftable from one position to another within a bushing that is provided with a plurality of ports that extend therethrough and at one end open at the interior wall surface of this bushing. These ports are provided in the bushing by such as a drilling operation. Consequently, the one end of these ports constitute a sharp edge which, it has been found in actual practice, causes cutting, tearing or other damage to the O-ring seals when they are moved over or past the one end of these ports as the spool valve is shifted from one position to another position within the bushing.
Accordingly, it is the general purpose of this invention to provide a novel air spring pressure control valve device that has a disc-type supply valve and a disc-type release valve which are actuated to an open position by movement of either a piston member or a permanent magnet that is repelled by a magnetic force.